Evidence for competing effects of body mass, hyperinsulinemia, insulin resistance, and androgens on leptin levels among lean, overweight, and obese women with polycystic ovary syndrome

"Association of Leptin with Polycystic Ovary Syndrome: a Systematic Review and Meta-Analysis"

Background

Serum leptin has been considered as an important measurable diagnostic and prognostic biomarker for polycystic ovarian syndrome (PCOS), although its evidence for use in clinical practice is limited. We aim to synthesize the available evidence on the clinical use of serum leptin values in PCOS by doing a systematic review and meta-analysis of studies.

Objective

To conduct a meta-analysis to determine the pooled effect size of the association of leptin levels in patients with PCOS.

Methods

We searched electronic databases, i.e., PubMed, Google Scholar, Web of Science, ClinicalTrials.gov, and Medline from inception to September 2020, keeping filters for human studies and published in the English language. We used the random-effects model if heterogeneity between the studies was > 50%; otherwise, a fixed-effect model was applied to determine the standardized mean difference with 95% CI for comparison of leptin level between cases and controls. All the statistical analyses were completed using software STATA version 13.

Results

The meta-analysis included a total of 35 studies involving 2015 cases and 1767 controls that suggested statistically significantly higher leptin levels in the women with PCOS as compared to controls (SMD, 1.76, 95% CI 1.28 to 2.23, P < 0.001). In the stratified analysis when only high methodological quality studies were included, we did not observe a statistically significant difference in the leptin level between PCOS and controls (SMD 0.68, 95% CI -0.09 to 1.46). Analysis restricted to low methodological quality studies observed statistically significant high leptin levels in PCOS women as compared to controls (SMD 2.24, 95% CI 1.65 to 2.83).

Conclusion

The available evidence suggests that elevated leptin levels may be associated with risk of PCOS as compared to controls; however, failure to observe the similar association in high methodological quality studies demands further well-designed adequately powered studies to validate the findings.

Obesity, but not hyperandrogenism or insulin resistance, predicts skeletal muscle mass in reproductive-aged women with polycystic ovary syndrome: A systematic review and meta-analysis of 45 observational studies

Women with polycystic ovary syndrome (PCOS) exhibit reduced muscle insulin-mediated glucose uptake, potentially attributed to altered muscle mass; however, this is inconclusive. Altered muscle mass may aggravate PCOS complications. Our systematic review and meta-analysis evaluated whether PCOS alters muscle mass and function. Databases (MEDLINE, Web of Science, Scopus) were searched through September 2, 2020, for studies documenting skeletal muscle mass (lean tissue mass) and function (strength) in PCOS and control groups. The primary outcome was total lean body mass (LBM) or fat-free mass (FFM). Data were pooled by random-effects models and expressed as mean differences and 95% confidence intervals. Forty-five studies (n = 3676 participants) were eligible. Women with PCOS had increased total (0.83 [0.08,1.58] kg; p = 0.03; I²  = 72.0%) yet comparable trunk (0.84 [-0.37,2.05] kg; p = 0.15; I²  = 73.0%) LBM or FFM versus controls. Results of meta-regression analyses showed no associations between mean differences between groups in total testosterone or homeostatic model assessment of insulin resistance and total or trunk LBM or FFM (All: p ≥ 0.75). Mean differences in body mass index (BMI) were associated with total (0.65 [0.23,1.06] kg; p < 0.01; I²  = 56.9%) and trunk (0.56 [0.11,1.01] kg; p = 0.02; I²  = 42.8%) LBM or FFM. The PCOS subgroup with BMI ≥ 25 kg/m² had greater total LBM or FFM versus controls (1.58 [0.82,2.34] kg; p < 0.01; I²  = 64.0%) unlike the PCOS subgroup with BMI < 25 kg/m² (-0.45 [-1.94,1.05] kg; p = 0.53; I²  = 69.5%). Appendicular lean mass and muscle strength data were contradictory and described narratively, as meta-analyses were impossible. Women with PCOS have higher total and trunk lean tissue mass attributed to overweight/obesity, unlike hyperandrogenism or insulin resistance.

Impact of Low Frequency Electro-acupuncture on Glucose and Lipid Metabolism in Unmarried PCOS Women: A Randomized Controlled Trial

OBJECTIVE

To explore the effect of electro-acupuncture (EA) on glucose and lipid metabolism in unmarried patients with polycystic ovary syndrome (PCOS).

METHODS

Fifty-four PCOS patients were equally randomized into true acupuncture group and sham acupuncture group (control) for totally 16 weeks of treatment by random method with a computerized randomization program. Patients in true acupuncture group accepted traditional acupuncture methods with EA and two sets of acupoint groups were used alternatively. The first set consisted of Zhongji (CV 3), Qihai (CV 6), Guilai (ST 29), Sanyinjiao (SP 6), Yinlingquan (SP 9), Hegu (LI4) and Baihui (GV 20), and the second set consisted of Tianshu (ST 25), ST 29, CV 3, CV 6, SP 6, Taichong (LR 3), Neiguan (PC) 6 and GV 20. Patients in the sham acupuncture group accepted shallow acupuncture methods through EA without electricity at 4 non-meridian points in each shoulder and upper arm. Outcome measures included body mass index (BMI), waist-hip-ratio (WHR), oral glucose tolerance test (OGTT), insulin release test, glucose and lipid metabolism indicators such as total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), adiponectin, leptin, visfatin, resistin, and interleukin (IL-6).

RESULTS

Twenty-six subjects in the true acupuncture group and 20 subjects in the sham group completed the clinical trial. After 16 weeks of treatment, no significant difference in the outcome measures were observed between the two groups (P>0.05). However, as compared with baseline data, a reduction in weight, BMI, hipline, WHR, fasting glucose, homeostatic model assessment of insulin sensitivity, visfatin and HDL-C, and an increase in resistin and IL-6 were observed in the true acupuncture group (P<0.05). In addition, a reduction in visfatin and an increase in TC were also observed in the sham group (P<0.05).

CONCLUSIONS

Acupuncture may have a beneficial effect in the treatment of PCOS by improving glucose and lipid metabolism. Moreover, the sham acupuncture may be not completely ineffective. Sham acupuncture may improve some of the aspects of the glucose and lipid metabolism of PCOS patients through a placebo effect. (Registration Nos. ChiCTR-TRC-12002529 and NCT01812161).

C-Reactive Protein, Fibrinogen, Leptin, and Adiponectin Levels in Women with Polycystic Ovary Syndrome

Background and Aim

We aimed to compare the levels of clinical, biochemical, hormonal, and metabolic parameters as well as serum CRP, fibrinogen, leptin, and adiponectin in cases with PCOS and control group to investigate whether they play a role in the etiology of the syndrome.

Materials and Methods

The present study included a total of 90 subjects, 45 subjects were diagnosed with PCOS (n = 45) and 45 subjects served as control group (n = 45). Serum CRP, fibrinogen, leptin, and adiponectin levels were analyzed for each subject.

Results

Serum CRP, fibrinogen, and leptin were found to be higher (statistically significant) in the group with PCOS as compared to the control group (p < 0.05). Serum Adiponectin was higher in the control group (statistically significantly) as compared with the patients in the PCOS group (p < 0.05).

Conclusion

CRP and fibrinogen (cardiac risk factor markers) increase in women with PCOS. The levels of leptin which affects metabolism increase, whereas the levels of adiponectin decrease.

Altered leptin, adiponectin, resistin and ghrelin secretion may represent an intrinsic polycystic ovary syndrome abnormality

The aim of the study was to investigate whether altered adipose tissue secretion of various adipokines is secondary to obesity, hyperandrogenism, and hyperinsulinemia or intrinsic to polycystic ovary syndrome (PCOS). This cross-sectional study included 151 women diagnosed with PCOS by the Rotterdam criteria and 95 healthy women matched by age, body mass index (BMI), and waist-to-hip ratio (WHR). Clinical, biochemical, and hormonal characteristics were assessed. Serum concentrations of ghrelin and adiponectin were found to be significantly lower and concentrations of leptin and resistin significantly higher in women with PCOS than in healthy women matched by age, BMI, and WHR. A PCOS diagnosis made the largest contribution to predicting serum levels of leptin, adiponectin, resistin, and ghrelin in all stepwise multiple regression models, which included PCOS diagnosis, BMI, WHR, luteinizing hormone, total testosterone, free testosterone and homeostatic model assessment of insulin resistance as independent predictors. Leptin, adiponectin, ghrelin and resistin levels may serve as independent biomarkers for the diagnosis of PCOS.

Body Composition, Metabolic Characteristics, and Insulin Resistance in Obese and Nonobese Women with Polycystic Ovary Syndrome

Objectives:

The objective was to compare body composition, metabolic characteristics, and insulin resistance between obese (body mass index [BMI] ≥25 kg/m²) polycystic ovary syndrome (PCOS) and nonobese PCOS (BMI <25 kg/m²) women and their age- and BMI-matched controls.

Materials and Methods:

A total of 81 PCOS women (Rotterdam criteria) (obese – 42; nonobese – 39) and 86 controls (obese – 42; nonobese –44) were recruited in this cross-sectional study. All women underwent a detailed assessment of clinical, anthropometric, and metabolic parameters, insulin resistance indices, and body composition measurements with visceral adipose tissue assessment (VAT) (dual-energy X-ray absorptiometry scan).

Results:

Of PCOS women, 27% (80% – obese PCOS; 20% – nonobese PCOS) were diagnosed with metabolic syndrome (International Diabetes Federation criteria), 35% of PCOS women (46% – obese PCOS; 54% – nonobese PCOS) had impaired glucose tolerance, and 7% of PCOS women (2/3^rd – obese PCOS; 1/3^rd – nonobese PCOS) had diabetes mellitus. Insulin resistance was seen in about 80% in obese PCOS women and 20% in nonobese PCOS women based on various insulin resistance indices such as fasting insulin (≥12.2 μU/ml), Homeostasis Model Assessment-Insulin Resistance (≥2.5), and Quantitative Insulin Sensitivity Check Index (<0.33). Total body fat, estimated (Est.) VAT, and corrected Est. VAT (corrected for body weight) were significantly increased (P = 0.0001) in both obese and nonobese PCOS women when compared to those of their age- and BMI-matched controls. However, corrected Est. VAT (corrected for body weight) was not significantly different between obese and nonobese PCOS women.

Conclusion:

Both obese and nonobese PCOS women when compared with their age- and BMI-matched controls were metabolically worse and had more visceral adiposity. Nonobese PCOS poses similar risk as that of obese PCOS in having similar amount of VAT (corrected for body weight).

Neuroendocrine Regulation of Food Intake in Polycystic Ovary Syndrome

Several peripheral and central signals are involved in the sophisticated regulation of food intake. Women with polycystic ovary syndrome (PCOS) are prone to consume a diet higher in saturated fat and foods with high glycemic index and show impaired appetite regulation and measures of satiety. As a consequence, obesity, mostly of the central type, is prevalent in the syndrome and worsens the endocrine and metabolic profile of the affected patients. This review article briefly analyzes the current knowledge about the neuroendocrine mechanisms underlying the interplay between feeding behavior, obesity, and reproductive abnormalities in PCOS.

Leptin Levels in Women With Polycystic Ovary Syndrome: A Systematic Review and a Meta-Analysis

OBJECTIVE

Conflicting results regarding leptin levels in women with polycystic ovary syndrome (PCOS) have been reported. We summarize all available evidence from human participant studies to evaluate leptin levels in PCOS.

DATA SOURCES

PubMed, ClinicalTrials.gov , and Web of Science databases were searched with English-language restriction for only human beings from the inception to December 31, 2015. Search terms included PCOS (polycystic ovary syndrome or PCOS) and leptin.

METHODS OF STUDY SELECTION

A total of 238 studies were reviewed, and a total of 19 studies, involving 991 women with PCOS and 898 controls, were eligible for our meta-analysis. Studies were eligible if provided leptin means and standard deviation in women with PCOS and healthy women controls.

RESULTS

Parameters, such as body mass index, insulin resistance (IR), and total testosterone, which may influence leptin levels were extracted. Data were collected and analyzed by RevMan 5.3 and Stata/SE14.0. The pooling analysis of all relevant studies revealed that leptin levels were significantly higher in patients with PCOS than in controls, with standardized mean difference of 1.62 (95% confidence interval: 1.01-2.23). However, the heterogeneity across studies was considerable and not eliminated in subgroup analyses. Meta-regression analysis further suggested that the heterogeneity might be relevant to variability in IR and study location.

CONCLUSION

Elevated leptin levels are detected in women with PCOS compared with non-PCOS controls. Higher leptin levels may be correlated with IR, metabolic disorder, infertility, and even cardiovascular disease risk in PCOS, which may contribute to the etiology and development of PCOS.

Leptin secretory dynamics and associated disordered eating psychopathology across the weight spectrum

OBJECTIVE

Leptin secretory dynamics across the weight spectrum and their relationship with disordered eating psychopathology have not been studied. Our objective was to compare leptin secretory dynamics in 13 anorexia nervosa (AN), 12 overweight/obese (OB) and 12 normal-weight women using deconvolution analysis.

METHODS

In this cross-sectional study conducted at a tertiary referral center, serum leptin levels were obtained every 20  min from 2000 to 0800  h. Dual energy X-ray absorptiometry was used to measure percent body fat. Disordered eating psychopathology was assessed by the Eating Disorders Examination-Questionnaire (EDE-Q) and the Eating Disorders Inventory-2 (EDI-2).

RESULTS

The groups differed for basal leptin secretion (BASAL) (P=0.02). Mean leptin pulse amplitude, pulse mass, total pulsatile secretion (TPS) and area under the curve (AUC) were significantly different between groups before and after adjustment for BASAL (P<0.0001 for all). Leptin AUC correlated strongly with TPS (r=0.97, P<0.0001) and less with BASAL (r=0.35, P=0.03). On multivariate analysis, only TPS was a significant predictor of leptin AUC (P<0.0001). TPS was inversely associated with most EDE-Q and EDI-2 parameters and the associations remained significant for EDE-Q eating concern (P=0.01), and EDI-2 asceticism, ineffectiveness and social insecurity (P<0.05) after adjusting for BASAL. These relationships were not significant when controlled for percent body fat.

CONCLUSION

Secretory dynamics of leptin differ across weight spectrum, with mean pulse amplitude, mean pulse mass and TPS being low in AN and high in OB. Pulsatile, rather than basal secretion, is the major contributor to leptin AUC. Decreased pulsatile leptin is associated with disordered eating psychopathology, possibly reflecting low percent body fat in AN.

The Preventive Effect of Zuogui Wan on Offspring Rats' Impaired Glucose Tolerance Whose Mothers Had Gestational Diabetes Mellitus

In this experiment, we used streptozotocin (STZ) to establish a model of gestational diabetes mellitus (GDM) rats, where Zuogui Wan was given to GDM rats. After pregnancy, offspring rats were divided into 4 groups: control group, high fat and sugar as the control group, GDM group, and Zuogui Wan GDM group. Rats in high fat and sugar as the control group, GDM group, and Zuogui Wan GDM group were fed with high fat and sugar diet. Rats in control group were fed the basic diet. The means of 2hPG were higher than 7.8 mmol·L⁻¹ and lower than 11.1 mmol·L⁻¹ on the rats of GDM group on week 15, and IGT models were successful. Body weight, abdominal fat weight, the ratio of abdominal fat weight and body weight, fasting plasma glucose, 2hPG, insulin, leptin, total cholesterol, and low density lipoprotein (LDL) of Zuogui Wan GDM group were significantly lower than GDM group. The level of adiponectin in Zuogui Wan GDM group was significantly higher than GDM group. And we concluded that giving Zuogui Wan to GDM rats can have a preventive effect on the offsprings' IGT induced by high fat and sugar diet.

Waist-to-hip ratio versus body mass index as predictors of fitness in women

The claim that men prefer women with low waist-to-hip ratios (WHR) has been vigorously disputed. We examine self-report data from 359 primiparous Polish women (with normal singleton births and healthy infants) and show that WHR correlates with at least one component of a woman's biological fitness (her first child's birth weight, a variable that significantly affects infant survival rates). However, a woman's Body Mass Index (BMI) is a better predictor of her child's neonatal weight in small-bodied women (<54 kg). The failure to find a preference for low WHR in some traditional populations may thus be a consequence of the fact that, even in western populations, body mass is a better predictor of fitness in those cases characterized by low maternal body weight.

Follicular fluid concentrations of lipids and their metabolites are associated with intraovarian gonadotropin-stimulated androgen production in women undergoing in vitro fertilization

CONTEXT

Although growing evidence points toward a role of lipotoxicity in the development of hyperandrogenesis, the main feature of polycystic ovary syndrome, few studies directly assessed this association in vivo in humans, and none targeted the ovarian milieu.

OBJECTIVE

The main objective of this study was to correlate follicular fluid (FF) T levels with lipids, lipid metabolites, and inflammation markers.

DESIGN

This was a cross-sectional study.

SETTING

Recruitment was performed in two fertility clinics at one private and one academic center.

PARTICIPANTS

Eighty women requiring in vitro fertilization were recruited during one of their scheduled visit at the fertility clinic. All women aged between 18 and 40 years with a body mass index between 18 and 40 kg/m(2) were invited to participate.

INTERVENTION(S)

There were no interventions.

MAIN OUTCOME MEASURE(S)

At the time of oocyte aspiration, FF was collected and analyzed for total T, lipids [nonesterified fatty acids (NEFAs) plus triglycerides], NEFA metabolites (acylcarnitines; markers of ineffective NEFAs β-oxidation), and inflammatory marker composition. The hypothesis being tested was formulated before the data collection.

RESULTS

FF T levels were significantly correlated with FF levels of lipids (r = 0.381, P = .001; independently of IL-6), acylcarnitines (r ≥ 0.255, all P = .008; not independently of lipids), and IL-6 (r = 0.300, P = .009, independently of lipids). Additionally, FF lipid levels were significantly and strongly correlated with acylcarnitines (r ≥ 0.594; all P < .001).

CONCLUSIONS

These results suggest that ovarian androgen production is related to intraovarian exposure to lipids, independently of inflammation and mainly through ineffective NEFA β-oxidation (as shown by higher acylcarnitine levels). Inflammation is also associated with intraovarian androgenesis, independently of lipids.

Study of Association of Leptin and Insulin Resistance Markers in Patients of PCOS

Polycystic ovary syndrome (PCOS) is a common endocrinological disorder among women of the reproductive age group with long term sequelae which include diabetes mellitus, hypertension and CAD. The present study was conducted to evaluate the association of leptin-an adipokine playing an important role in carbohydrate metabolism and markers of insulin resistance among women with PCOS. Sixty diagnosed cases of PCOS as per Rotterdam criteria were enrolled in this study after informed written consent. Insulin resistance was estimated using the homeostatic model assessment-insulin resistance (HOMA-IR). HOMA-IR was calculated as the product of the fasting plasma insulin value (mU/ml) and the fasting plasma glucose value (mg/dl), divided by 405 and HOMA β was calculated as 360 × [insulin]/([glucose] - 63) % (glucose in mg/dl). Estimation of serum leptin levels was done by ELISA using leptin ELISA kit from (DRG). A positive correlation of serum leptin levels was observed with markers of insulin resistance. Multiple regression analysis with HOMA-IR as dependent variable demonstrated a statistically significant contribution of fasting insulin levels. This study highlights the role of leptin in alterations in carbohydrate metabolism in patients with PCOS.

Adipocyte biology in polycystic ovary syndrome

Polycystic Ovary Syndrome (PCOS) is a common endocrinopathy that is associated with an adverse metabolic profile including insulin resistance. There is a clear association between obesity, the development of PCOS and the severity of its phenotypic, biochemical and metabolic features. Evidence to support this link includes data from epidemiological, pathophysiological and genetic studies. Given the importance of obesity in the development and manifestation of PCOS, ongoing research into the many facets of adipocyte biology in women with the condition is important and should continue to be a priority. In this review article, we discuss the existing literature on fat distribution, adipokines, adipocyte hypertrophy and adipocyte steroid metabolism in women with PCOS.

Kisspeptin, leptin, and retinol-binding protein 4 in women with polycystic ovary syndrome

OBJECTIVES

To compare plasma kisspeptin, serum leptin, and serum retinol-binding protein 4 (RBP4) levels in women with and without polycystic ovary syndrome (PCOS) and to correlate these among each other and with clinical, hormonal, and metabolic parameters.

METHODS

Ninety women, including 54 women with PCOS and 36 without PCOS, participated in this study. For all patients, history and physical examinations were performed and blood samples were collected between days 3 and 8 of a spontaneous bleeding episode in the PCOS group and during normal menses of controls. Plasma kisspeptin, serum leptin, and serum RBP4 levels were measured using specific commercial assays.

RESULTS

Kisspeptin, leptin, and RBP4 levels were significantly higher in the PCOS group than in controls. Kisspeptin and RBP4 levels were significantly higher among obese PCOS patients than controls. Leptin levels were higher among obese PCOS patients than non-obese PCOS patients or controls. Kisspeptin and leptin levels of PCOS patients were significantly correlated with RBP4 levels. When only obese PCOS patients were analyzed, kisspeptin levels correlated with only the free androgen index.

CONCLUSIONS

These findings suggest that kisspeptin, leptin, and RBP4 are associated with metabolic disturbances in women with PCOS.

Associations of testosterone and sex hormone binding globulin with adipose tissue hormones in midlife women

OBJECTIVE

Regulators of adipose tissue hormones remain incompletely understood, but may include sex hormones. As adipose tissue hormones have been shown to contribute to numerous metabolic and cardiovascular disorders, understanding their regulation in midlife women is of clinical importance. Therefore, we assessed the associations between testosterone (T) and sex hormone binding globulin (SHBG) with leptin, high molecular weight (HMW) adiponectin, and the soluble form of the leptin receptor (sOB-R) in healthy midlife women.

DESIGN AND METHODS

Cross-sectional analyses were performed using data from 1,881 midlife women (average age 52.6 (±2.7) years) attending the sixth Annual follow-up visit of the multiethnic Study of Women's Health Across the Nation.

RESULTS

T was weakly negatively associated with both HMW adiponectin and sOB-R (r = -0.12 and r = -0.10, respectively; P < 0.001 for both), and positively associated with leptin (r = 0.17; P < 0.001). SHBG was more strongly and positively associated with both HMW adiponectin and sOB-R (r = 0.29 and r = 0.24, respectively; P < 0.001 for both), and more strongly and negatively associated with leptin (r = -0.27; P < 0.001). Adjustment for fat mass, insulin resistance, or waist circumference only partially diminished associations with HMW adiponectin and sOB-R, but attenuated associations with leptin. In conclusion, in these midlife women, lower SHBG values, and to a lesser extent, higher T levels, were associated with lower, or less favorable, levels of adiponectin and sOB-R, independent of fat mass.

CONCLUSIONS

These data suggest that variation in these adipose hormones resulting from lower SHBG levels, and possibly, though less likely, greater androgenicity, may contribute to susceptibility for metabolic and cardiovascular outcomes during midlife in women.

Dietary intake, glucose metabolism and sex hormones in women with polycystic ovary syndrome (PCOS) compared with women with non-PCOS-related infertility

The present study investigated dietary intake, glucose metabolism and sex hormones in women with polycystic ovary syndrome (PCOS). A total of forty-five women (aged 25–40 years) with PCOS and 161 control women (aged 25–43 years) with non-PCOS-related infertility were recruited. Anthropometry, glucose tolerance and sex hormones were determined and dietary intake was assessed. Women with PCOS had lower serum sex hormone-binding globulin and increased BMI, waist:hip ratio, luteinising hormone, ratio of luteinising hormone: follicle-stimulating hormone, testosterone and free androgen index (FAI). Postprandial glucose, fasting insulin and insulin resistance were elevated in women with PCOS. Women with PCOS had reduced energy and carbohydrate intake but higher fat intake. Serum sex hormone-binding globulin level was negatively associated with BMI in both groups and negatively correlated with macronutrient intake in the PCOS group with hyperandrogenism. However, FAI was positively correlated with BMI, waist circumference and glucose metabolic parameters in both groups. Therefore, women with PCOS consume lower energy and carbohydrate compared with those with non-PCOS-related infertility and macronutrient intake is only negatively associated with serum sex hormone-binding globulin level in the PCOS group with hyperandrogenism.

Novel inflammatory markers in overweight women with and without polycystic ovary syndrome and following pharmacological intervention

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with reproductive and metabolic abnormalities.

AIM

The aim of this study was to assess novel inflammatory markers [adipokines leptin, adiponectin, and leptinadiponectin ratio (L/A)] in overweight women with and without PCOS and to examine alterations in these markers [aldosterone, leptin, adiponectin, and L/A] with pharmacological interventions modulating insulin resistance (IR) in PCOS.

MATERIALS/SUBJECTS AND METHODS

Overweight age, and body mass index (BMI)-matched women with (no.=80) or without PCOS (no.=27) were assessed cross-sectionally. Subjects with PCOS were then randomised to 6 months metformin (1 g b.d, no.=26) or oral contraceptive pill (OCP) (35 g ethinyl estradiol/2 mg cytoproterone acetate, no.=30). Outcome measures were leptin, adiponectin, L/A, aldosterone, highly sensitive C-reactive protein, lipid profile, IR, and androgen levels.

RESULTS

Leptin levels were lower (156.4+/-85.9 vs 208.5+/-105.2 ng/ml, p=0.015) while adiponectin and L/A were not different between women with and without PCOS. Following intervention, IR increased for the OCP and decreased for metformin, however leptin and aldosterone decreased equivalently with the OCP and metformin with no difference between each treatment (p=0.583 and p=0.801, respectively). There was no change in adiponectin or L/A with the OCP or metformin. On multiple regression, the only baseline predictor of leptin was BMI (r(2)=0.485, p<0.001) and the strongest predictor of change in leptin was change in weight (r(2)=0.402, p<0.001).

CONCLUSIONS

Alterations in leptin between women with and without PCOS and following pharmacological interventions are primarily related to adiposity and not IR. Aldosterone was reduced equivalently with metformin and the OCP despite differential effects on IR.

Leptin levels in relation to marital status and neuroendocrine function in Iraqi females with polycystic ovary syndrome

The present study was designed to evaluate the relationship between serum leptin levels and the hormones related to fertility in Iraqi females with polycystic ovary syndrome (PCOS) and marital status. This study was conducted during the period from July to December 2007. Twenty-four women (12 married and 12 unmarried) with PCOS and not maintained on any type of therapy were included in the study. Twelve healthy and normal ovulatory women with an age range matched with that of PCOS women were included. After an overnight fasting, blood samples were drawn from all women at random days. While in those with regular menstrual cycles, blood samples were obtained during the follicular phase of the cycle, except for samples utilized for the assay of progesterone that performed in the day 21 of the cycle (luteal phase). After preparation of serum, the levels of leptin, luteinizing hormone (LH), follicle-stimulation hormone (FSH), progesterone, testosterone and prolactin were analyzed. Both groups of PCOS patients showed significantly lower levels of serum leptin, while prolactin, LH and FSH and testosterone were significantly elevated compared to controls. No significant differences were reported among PCOS patients with different marital status. In conclusion, impaired plasma leptin levels in PCOS women were associated with impaired endocrinological parameters related to fertility.

Alteration of ghrelin-neuropeptide Y network in obese patients with polycystic ovary syndrome: role of hyperinsulinism

OBJECTIVE

Insulin, ghrelin, neuropeptide Y (NPY) and leptin interact in the regulation of energy homeostasis. Most of these signals are altered in polycystic ovary syndrome (PCOS), which is characterized by a high prevalence of obesity. The present study was conducted to evaluate ghrelin-NPY and ghrelin-leptin interplays in relation to insulin secretion in obese PCOS subjects.

DESIGN

Pilot prospective study.

PATIENTS

Seven obese PCOS women and seven age-weight matched controls.

MEASUREMENTS

Hormonal measurements, oral glucose tolerance test (OGTT) and a ghrelin test (1 microg/kg i.v. bolus). PCOS patients repeated the clinical work-up after 4 months of metformin treatment (1500 mg/day orally).

RESULTS

At baseline, PCOS women showed a significantly higher insulinaemic response to the OGTT compared to controls (P < 0.05). In basal conditions, PCOS women exhibited lower NPY levels than controls (P < 0.01). Ghrelin injection markedly increased NPY in controls (P < 0.01), whereas PCOS women showed a deeply blunted NPY response to the stimulus (area under the curve--AUC-NPY: P < 0.01 vs. controls.). Metformin treatment induced a significant decrease in insulin levels (P < 0.01) and the concomitant recovery of NPY secretory capacity in response to ghrelin (AUC-NPY: P < 0.05 vs. baseline) in PCOS women. Leptin levels, which were similar in the two groups, were not modified by ghrelin injection; metformin did not affect this pattern.

CONCLUSION

Hyperinsulinaemia seems to play a pivotal role in the alteration of NPY response to ghrelin in obese PCOS women. This derangement could be implicated in the physiopatology of obesity in these patients.

Metformin treatment does not affect total leptin levels and free leptin index in obese patients with polycystic ovary syndrome

Leptin, particularly in its free form, is deeply involved in the regulation of energy balance. Insulin was suggested to influence plasmatic leptin levels and soluble leptin receptor in humans. However, this study indicates that metformin treatment, although improving insulin levels, does not exert a significant effect on either total leptin level or free leptin index in obese women with hyperinsulinemia and PCOS.

Serum Levels of Leptin and Homocysteine in Women with Polycystic Ovary Syndrome and Its Relationship to Endocrine, Clinical and Metabolic Parameters

We examined the relationship between endocrine, clinical and metabolic parameters in 35 women (mean age 27.3 years) with polycystic ovary syndrome (PCOS) and 30 age- and body mass index-matched normal ovulatory women. In PCOS women, serum leptin, homocysteine, insulin, insulin-like growth factor-1, insulin-like growth factor binding protein-3 levels and the insulin resistance index (HOMA-IR) were significantly higher, while sex hormone-binding globulin and high-density lipoprotein cholesterol levels were lower compared with healthy women. Serum luteinizing hormone (LH), estradiol (E2), androstenedione, testosterone and dehydroepiandrosterone sulphate levels were found to be significantly higher in PCOS women compared with healthy women. The levels of E2, LH and testosterone were positively correlated with leptin levels in PCOS women. Similarly, androstenedione levels and HOMA-IR were positively correlated with homocysteine levels and insulin levels were positively correlated with LH. We conclude that increased homocysteine levels, hyperandrogenaemia, insulin resistance and impaired lipid metabolism contribute to the risk of premature atherosclerosis in PCOS women.

Effects of ghrelin administration on endocrine and metabolic parameters in obese women with polycystic ovary syndrome

INTRODUCTION

The novel peptide ghrelin displays multiple endocrine and non-endocrine actions. Its strong GH-releasing activity in humans has long been recognized. However, in obesity, ghrelin administration induces a blunted GH secretion, enhances glucose and reduces insulin levels. The effects of ghrelin administration have not been investigated in polycystic ovary syndrome (PCOS), which can be associated with obesity, hyperinsulinism, and GH hyposecretion. Leptin is a mediator for energy balance opposed to ghrelin; both of them are supposed to act as regulators of reproductive functions.

AIM OF THE STUDY

Evaluate the endocrine and metabolic response to ghrelin administration in PCOS obese patients compared to body mass index (BMI)-matched and normal weight women.

MATERIALS AND METHODS

Nine obese PCOS patients (BMI: 35.4+/-1.2 kg/m(2)) (OB PCOS), 6 obese controls (BMI: 38.4+/-1.1 kg/m(2)) (Ob), and 6 normal-weight women (BMI: 23+/-0.6 kg/m(2)) (NW) were enrolled in the study. In all patients we performed: 1) basal hormonal evaluation including FSH, LH, estradiol, testosterone, androstenedione, DHEAS, SHBG, 17-hydroxyprogesterone (17OHP), IGF-I, free T3 (FT3), free T4 (FT4) and ghrelin levels; 2) metabolic evaluation as follows: concentration of non-esterified fatty acid (NEFA) and oral glucose tolerance test (OGTT) (75 g); homeostasis model assessment (HOMA); glucose and insulin response to ghrelin administration (1 microg/kg); 3) measurement of GH, PRL, TSH, and leptin levels after infusion of ghrelin.

RESULTS

Administration of ghrelin increased glucose and reduced insulin levels in both Ob and OB PCOS. Moreover, ghrelin enhanced GH and PRL levels in all groups but it did not modify TSH and leptin levels. GH peak and area under the curve (AUC) in OB PCOS and Ob were lower than controls (p<0.05). Similar PRL peak and AUC values were observed in all groups.

CONCLUSIONS

In both obese and PCOS obese patients, leptin levels are not influenced by ghrelin administration. Moreover, the GH response after ghrelin administration is blunted. However, ghrelin exerts glucose- enhancing and insulin-lowering effects, the latter absent in NW.

Leptin secretory burst mass correlates with body mass index and insulin in normal women but not in women with polycystic ovary syndrome

Leptin secretion exhibits a pulsatile, circadian pattern and may play a role in reproduction. No previous studies have compared leptin secretory burst characteristics in normal eumenorrheic women and women with polycystic ovary syndrome (PCOS) who are appropriately matched for body mass index (BMI). To determine if leptin secretory burst characteristics and/or the relationships of BMI, insulin, or testosterone to these characteristics differ between PCOS and normal women, we studied 9 normal eumenorrheic women and 9 women with PCOS. Each woman underwent blood sampling every 10 minutes for 24 hours to measure leptin and insulin under controlled conditions. Leptin secretory bursts were identified and characterized using multiparameter deconvolution procedures (Deconv), and the 24-hour periodicity of leptin was characterized with cosinor analysis. Relationships between BMI, area under the curve (AUC) insulin, and testosterone and leptin secretory burst characteristics in PCOS and normal women were sought using linear regression. There were no significant differences in mean serum leptin concentrations or in secretory burst characteristics between PCOS and normal women. Although the 24-hour serum leptin concentration correlated with BMI in both normal and PCOS women, leptin secretory burst mass correlated with BMI only in normal women. Similarly, the 24-hour serum leptin concentration correlated with serum insulin AUC in both normal and PCOS women; but insulin AUC correlated with leptin burst mass only in normal women. Although there was a strong trend toward a correlation between both mean 24-hour serum leptin concentration and leptin secretory burst mass with the serum testosterone concentration in normal women, such trends were not seen in PCOS women. Both normal and PCOS women exhibited a diurnal rhythm of leptin secretion with the peak occurring at night. However, neither the peak amplitude nor the timing of the peak amplitude differed between normal and PCOS women. The presence of strong relationships between BMI and insulin with both mean serum leptin and leptin secretory burst mass in normal women as opposed to PCOS women suggests that the mechanisms subserving leptin secretion differ in these 2 groups.

Why does ovarian surgery in PCOS help? Insight into the endocrine implications of ovarian surgery for ovulation induction in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex disorder with heterogeneity of clinical and endocrine features. Ovarian surgery for ovulation induction has been used in the management of clomiphene citrate-resistant anovulatory women with PCOS. Various types of ovarian surgery have been employed (wedge resection, electrocautery, laser vaporization, multiple ovarian biopsies and others) and all procedures result in an altered endocrine profile after surgery. The mechanism behind the reversal of endocrinological dysfunction in PCOS after ovarian surgery remains incompletely understood. This review scans the literature systematically to identify the endocrine changes after ovarian surgery in PCOS, in order to glean some knowledge of the mechanism involved. After ovarian surgery in PCOS, a rapid reduction in serum levels of all ovarian hormones is seen, in combination with increased serum levels of pituitary hormones. Folliculogenesis is then initiated and ovarian hormone production increases, synchronically with a reduction of pituitary hormones. Continuation of follicle growth in subsequent cycles after ovarian surgery occurs in an environment with less androgens and lower LH and FSH levels compared with pretreatment levels. The endocrine changes found after ovarian surgery in PCOS women seem to be governed by the ovaries themselves. Rapid reduced secretion of all ovarian hormones restores feedback to the hypothalamus and pituitary, resulting in appropriate gonadotrophin secretion. Initiation of follicular development seems to be induced by increasing FSH levels following a reduction of the follicle excess and (intra-ovarian) androgen levels. Additionally, anti-Müllerian hormone and gonadotrophin surge attenuating factor probably have a role in the endocrine changes.

Obesity and polycystic ovary syndrome

The aetiology of Polycystic Ovary Syndrome (PCOS) is complex and multifactorial. There is much evidence, however, to suggest that adipose tissue plays an important role in the development and maintenance of PCOS pathology. There is a close correlation between adiposity and symptom severity in women with PCOS, and even modest reductions in weight generally translate into significant improvements in menstrual regularity, fertility and hyperandrogenic features. This review article considers the various mechanisms that might underlie this link between excess adiposity and PCOS - including the effects of differential insulin sensitivity, abnormal steroid hormone metabolism and adipocytokine secretion. Greater attention to the therapeutic options available to reduce the impact of excess adiposity on ovarian and metabolic function is essential to the management of PCOS.

Polycystic ovary syndrome: etiology and pathogenesis

OBJECTIVE

To provide a review of the pathogenesis of polycystic ovary syndrome.

DESIGN

Literature survey.

RESULT(S)

Three major pathophysiologic hypotheses have been proposed to explain the clinical findings of polycystic ovary syndrome (PCOS) related to three major laboratory findings: the LH hypothesis, the insulin hypothesis and the ovarian hypothesis. Although the presence of many small follicles with a high androgen to estrogen ratio was first thought to represent a high rate of follicular atresia in polycystic ovaries, recent studies have demonstrated that the granulosa cells are viable and able to respond to FSH stimulation with normal increases in estradiol production. Thus, a new hypothesis has arisen that FSH activity is somehow blocked at the ovarian level.

CONCLUSION(S)

PCOS is a syndrome involving defects in primary cellular control mechanisms that result in the expression of chronic anovulation and hyperandrogenism. In this syndrome, the relation between the various parameters is of particular interest. These relations constitute the cornerstone of the pathogenesis of PCOS. The fact that the pathogenesis of PCOS has not yet been clarified, despite the plethora of relative information, may be the result of a general way of thinking in the interpretation of several scientific data, and especially those that refer to biochemical phenomena. The use of the various models of the theory of chaos, that permits a concrete approach for the interpretation of data, may constitute an optional procedure for the future understanding of the association of different parameters and their disturbances in the pathogenesis of the polycystic ovary syndrome.

Serum soluble leptin receptor levels and free leptin index in women with polycystic ovary syndrome: relationship to insulin resistance and androgens

OBJECTIVE

To evaluate levels of soluble receptor (sOB-R) and free leptin in women with polycystic ovarian syndrome (PCOS) and note any relationships with insulin resistance, adiposity, and androgens. Leptin is an adipokine that circulates in a free form and bound to an sOB-R. Only free leptin is biologically active.

DESIGN

Prospective, case-control study.

SETTING

University-based reproductive endocrinology practice.

PATIENT(S)

Forty women with PCOS and severe insulin resistance and 15 body mass index (BMI)-matched ovulatory controls.

INTERVENTION(S)

Measurements of serum insulin, leptin, sOB-R at fasting and during a standard oral glucose tolerance test (OGTT), and measurements before and after treatment with rosiglitazone.

MAIN OUTCOME MEASURE(S)

Fasting glucose, insulin, leptin, sOB-R, T, and DHEAS levels in women with PCOS and controls were measured to investigate the relationship of sOB-R and the free leptin index (FLI) to insulin, adipocity, and androgens and to investigate the effect of acute hyperinsulinemia during OGTT and the effect of improvement of insulin resistance with rosiglitazone on the leptin system. FLI was calculated by dividing leptin levels by sOB-R.

RESULT(S)

Total leptin and FLI correlated significantly with BMI in both patients with PCOS and in controls. There was a significant negative correlation between DHEAS and sOB-R in PCOS. Leptin, sOB-R, and FLI were not significantly different in the two groups, and neither sOB-R nor FLI correlated with insulin or glucose levels. The sOB-R levels increased significantly 3 hours after oral glucose ingestion, resulting in a significant decline in FLI.

CONCLUSION(S)

[1] Adiposity rather than insulin resistance appears to be the main determinant of leptin levels and FLI. [2] Acute increase in insulin levels during OGTT is associated with an increase in levels of sOB-R. [3] DHEAS may play a role in leptin bioavailability by modulating sOB-R levels.

Adipokines: implications for female fertility and obesity

Obesity is associated with a diverse set of metabolic disorders, and has reproductive consequences that are complex and not well understood. The adipose tissue-produced leptin has dominated the literature with regards to female fertility complications, but it is pertinent to explore the likely role of other adipokines--adiponectin and resistin--as our understanding of their biological functions emerge. Leptin influences the developing embryo, the functioning of the ovary and the endometrium, interacts with the release and activity of gonadotrophins and the hormones that control their synthesis. In this review such biological actions and potential roles of the adipokines leptin, adiponectin and resistin are explored in relation to female fertility and the complexity of the obese metabolic state.

Serum leptin levels and insulin resistance are associated with gallstone disease in overweight subjects

AIM: To establish an association between the serum leptin levels and the development of gallstone disease (GD).

METHODS: We carried out a non-matched case-controlled study in a university hospital in Mexico City. Two hundred and eighty-seven subjects were included: 97 cases with gallstones and 190 controls. Body mass index (BMI), fasting plasma leptin, insulin, serum lipid, and lipoprotein levels were measured. Insulin resistance was calculated by homeostasis model assessment (HOMA-IR). Unconditional logistic regression analysis (univariate and multivariate) stratified by BMI was used to calculate the risk of GD.

RESULTS: The multivariate conditional regression analysis revealed a model for those patients with BMI <30. The selected variables in the model were HOMA-IR index with OR = 1.31, P = 0.02 and leptin higher than median with OR = 2.11, P = 0.05. In the stratum of BMI ≥30, we did not find a useful model.

CONCLUSION: We concluded that insulin resistance and the development of GD appears to be associated with serum leptin levels in subjects with overweight, but not in obese subjects with similar metabolic profiles.

Serum leptin elevation in obese women with PCOs: a continuing controversy

PURPOSE

To evaluate leptin levels in a sample of obese women with PCOS and compare the results with obese and non-obese control, to be ultimately correlated with BMI, and insulin sensitivity.

METHODS

Leptin and insulin assays by immuno-radiometric method, glucose assay by enzymatic colorimetric method.

RESULTS

Leptin levels were significantly different between obese and non-obese subjects, and were significantly different between insulin resistant and non-insulin resistant obese PCOS, but were not significantly different between obese non-insulin resistant PCOS, and obese controls.

CONCLUSIONS

Body mass index and insulin resistance are the two main factors governing serum leptin levels.

Men’s ratings of female attractiveness are influenced more by changes in female waist size compared with changes in hip size

Women's attractiveness has been found to be negatively correlated with waist-to-hip ratio (WHR) in many studies. Two components of this ratio can, however, carry different signals for a potential mate. Hip size indicates pelvic size and the amount of additional fat storage that can be used as a source of energy. Waist size conveys information such as current reproductive status or health status. To assess which of these two dimensions is more important for men's perception of female attractiveness, we used a series of photographs of a woman with WHR manipulated either by hip or waist changes. Attractiveness was correlated negatively with WHR, when WHR was manipulated by waist size. The relation was inverted-U shape when WHR was changed by hip size. We postulate that in westernized societies with no risk of seasonal lack of food, the waist, conveying information about fecundity and health status, will be more important than hip size for assessing a female's attractiveness.

PCOS: an ovarian disorder that leads to dysregulation in the hypothalamic–pituitary–adrenal axis?

This review focuses on the role of the ovaries in the pathogenesis of the polycystic ovarian syndrome. In particular, the failure of follicular development, hypothalamo-pituitary dysregulation, alterations in adrenal steroid output and derangement of intermediary metabolism are discussed in the context of the ovaries. It is concluded that the central and adrenal alterations associated with PCOS are unlikely to be primary but rather are secondary to the events within the ovary.

Serum leptin levels correlate with obesity parameters but not with hyperinsulinism in women with polycystic ovary syndrome

OBJECTIVE

To examine serum leptin concentrations in obese and lean patients with polycystic ovary syndrome (PCOS) to assess whether the changes in leptin levels are due to obesity or hormonal alterations.

DESIGN

Controlled clinical study.

SETTING

Academic research environment.

PATIENT(S)

Obese and lean women with PCOS.

INTERVENTION(S)

Blood samples were collected before and after food consumption.

MAIN OUTCOME MEASURE(S)

Serum leptin and insulin levels.

RESULT(S)

Serum leptin concentrations were significantly correlated with body mass index (r = 0.649) and also with HOMA (r = 0.535). However, after controlling for body mass index in a partial correlation analysis, no significant correlation was found between serum leptin levels and HOMA or hyperinsulinemia. While lean patients with PCOS had a significant correlation between leptin concentrations and obesity parameters, they did not show any significant correlation with insulin resistance parameters.

CONCLUSION(S)

Although leptin concentrations in women with PCOS correlate with insulin resistance/hyperinsulinemia, this is related only to obesity.

Leptin and its association with polycystic ovary syndrome: a twin study

Polycystic ovary syndrome (PCOS) is a common endocrinopathy with symptoms such as obesity, insulin resistance and hyperandrogenemia. PCOS might be the result of a genetic disorder. Genetic discrepancy in the production of leptin, a product of the obesity gene, may lead to various endocrinopathies such as PCOS. The objective of this study was first, to ascertain the incidence of PCOS, using the gold standard; second, to ascertain the genetic property of leptin; and third, to evaluate the association between leptin concentration and PCOS. A total of 154 Tehran-resident female-female twins were studied. They included 48 pairs of monozygotic (MZ) and 29 pairs of dyzygotic (DZ) twins, aged 15-45 years. Clinical, ultrasound and biochemical findings were used to diagnose PCOS. The incidence of PCOS using biochemical and clinical features was 16.2%. The correlation coefficient between serum leptin levels of MZ twins was higher than that of the DZ twins. The serum level of leptin was similar between subjects with or without PCOS, irrespective of their zygosity. It was concluded that the incidence of PCOS is high among twins, and that leptin is likely to be genetically determined, although the effect of environmental factors cannot be denied. This study did not find any association between the diagnosis of PCOS and leptin level. However, the link between the two may lie with other entities such as eating disorders and/or obesity.

Body composition, fat distribution and metabolic characteristics in lean and obese women with polycystic ovary syndrome

The polycystic ovary syndrome (PCOS), characterized by chronic anovulation and hyperandrogenism, has many features of metabolic syndrome and can be considered a metabolic disease. Approximately 50% of patients with PCOS are overweight or obese with abdominal fat accumulation. Some metabolic alterations and abdominal fat distribution have also been reported in lean women with PCOS. The aim of this study was to evaluate the effect, if any, of obesity on metabolic features, body composition and fat distribution in patients with PCOS. Body composition and abdominal fat distribution (evaluated by DEXA), waist circumference, blood pressure, lipid profile, glucose tolerance and homeostasis model assessment index were determined in 23 lean [mean age 23 +/- 5 yr, mean body mass index (BMI) 22 +/- 2 kg/m2] and 27 overweight-obese (mean age 21 +/- 5 yr, mean BMI 32 +/- 5 kg/m2) patients with PCOS and in 20 age- and weight-matched eumenorrhoic women. Patients exhibited slight but non-significant differences in metabolic parameters, waist circumference, blood pressure and total and abdominal fat content compared with weight-matched controls. None of the lean subjects suffered from metabolic syndrome according to the National Cholesterol Education Program--Adult Treatment Panel III (NCEP-ATPIII) criteria as opposed to 10 overweight-obese patients and three overweight-obese control subjects (37% and 33.3% of each subgroup, respectively). Our data do not show significant metabolic alterations in lean PCOS women. Results indicate that obesity seems to underpin the metabolic alterations exhibited by the overweight-obese patients. However, since women with PCOS are at increased cardiovascular risk, further studies are needed to evaluate metabolic alterations and body composition in these patients.

A randomized trial of the effects of two types of short-term hypocaloric diets on weight loss in women with polycystic ovary syndrome

OBJECTIVE

We performed this study as a pilot experiment to investigate the short term effects of two diets of varying composition on weight loss as the primary outcome in obese women with polycystic ovary syndrome (PCOS) seeking fertility.

DESIGN

Randomized clinical trial.

SETTING

Academic medical center.

PATIENT(S)

Thirty-five obese women with PCOS.

INTERVENTION(S)

We examined the effects of a 1-month dietary intervention on the PCOS phenotype. Participants were randomized to one of two energy-restricted diets; high protein (HP: 30% protein, 40% carbohydrate, and 30% fat) or high carbohydrate (HC: 15% protein, 55% carbohydrate, and 30% fat). The fat content was held constant in both diets.

MAIN OUTCOME MEASURE(S)

Primary - change in body weight; Secondary - biometric, hormonal, lipid and lipoprotein, and markers of glucose homeostasis and energy metabolism.

RESULT(S)

Twenty-six women completed the study. Both the HP (-3.7 +/- 1.9 kg) and HC (-4.4 +/- 1.5 kg) diets resulted in significant weight loss, but there was no significant difference in mean weight loss between the two groups. There were also no differences between diets on a variety of measures including circulating androgens, measures of glucose metabolism, and leptin. However, the effects of a hypocaloric diet per se on improving metabolic and reproductive abnormalities in a group of PCOS women were marked by a decline in circulating androgens (P=.03), fasting and area under the curve (AUC) insulins (P<.05) on a 3-hour oral glucose tolerance test (OGTT), and fasting and AUC leptin levels (P<.0001). There was a high prevalence of menstrual bleeding during the trial (14 out of 26 patients).

CONCLUSION(S)

Those who completed the short-term hypocaloric diet had a significant weight loss and a significant improvement in their reproductive and metabolic abnormalities. There was no increased benefit to a high-protein diet. Future diet studies evaluating the ideal composition of a hypocaloric diet in women with PCOS will require a large study population, and will most likely require a multicenter trial.

Serum leptin and body composition in polycystic ovarian syndrome

BACKGROUND

The role of leptin in polycystic ovarian syndrome (PCOS) is unclear. We investigated the relationship between serum leptin levels, body composition and insulin resistance in polycystic ovarian syndrome (PCOS).

METHODS

We analyzed differences between 27 patients with PCOS and 25 control subjects in serum glucose and leptin levels, insulin resistance, body fat mass, lean body mass, and water volume.

RESULTS

Serum leptin was significantly correlated with basal insulin levels, BMI and IR in both groups (P<0.01). Fat mass, fat percentage, lean mass and water volumes were positively correlated and lean percentage and water percentage were negatively correlated with leptin levels (P<0.05). Leptin levels were significantly different between the groups in a multivariate regression analysis after correcting for the difference in BMI and body fat percentage (P<0.05). When the effects of fat percentage on serum leptin were eliminated, the levels were significantly different between the PCOS and control groups, and were statistically more powerful than BMI (P<0.01).

CONCLUSION

These findings support the idea that factors other than excess fat mass or fat-free mass might be important in the regulation of serum leptin levels in PCOS.